When you make a list of the most essential items you need to survive, the list can be short. The reality is that as much as we have in our houses and in our lives on a daily basis that we think we can’t do without, the things that we really cannot do without is very short. That said, as few of them as there are, water is surely at or near the very top of the list.

Daily water intake is very important to good health under normal conditions. It’s estimated that the human body needs about two quarts of water each day to function properly. Factor in conditions that are more stressful and take a significant toll on the body, and the need for water becomes even greater.

Keeping large supplies of drinking water on hand for emergencies is a good idea, but depending on the nature of your emergency situation, you might also have to access other resources of water that will need to be purified; protracted sorts of survival situations may last longer than what you have on hand in reserve will cover, and so it is imperative that you familiarize yourself with some basic methods of water purification.

A great way to purify water is with water purification tablets. The principal purifying ingredient in these tablets is iodine, which attacks the microorganisms in the water. After about 30 minutes, the water is safe to drink. Getting water purification tablets is easy; a quick Google search for them will return a lot of useful results.

Similar to tablets is something called tincture of iodine. 2% iodine tincture is a common antiseptic, and is a great way to purify water. It generally comes in a small bottle with a dropper application; about 5 drops per quart of water should do the trick (as with the tablets, let the water sit for about 30 minutes before drinking it).

Lastly, there is the old standby of boiling water. If you have a way to construct a fire or have another heat source that will allow you to do this, it will work fine. To purify, you will want to boil the water at least a minute before drinking it if you’re at sea level, and for an additional minute for every 1,000 feet above sea level at which you’re located.

The ability to hydrate at all times is essential. As the human body is made up of 90 percent water, the ingestion of plenty of water is necessary for it to maintain its efficiency. Having a good reserve supply of drinking water on-hand is a no-brainer, but it is also smart to know how you can purify water that is not already potable (drinkable). That said, as with all survival preparations, take the time in advance to get your supplies in order; water purification tablets and other means of purifying water are very useful, but cannot do you any good in an emergency if they’re still sitting on a survival supply company’s warehouse shelves.

Are you familiar with the “just-in-time” inventory system used now throughout the modern world as a way for manufacturers and retailers to control costs? If not, you need to become acquainted with what it is and, more importantly, what it means to you when distressed conditions arise quickly and essentially wipe out any preparation time that might have remained if the onset of trouble occurred at a much slower pace.

Have you ever gone into a retail store to look for an item, only to find its labeled space on the shelf but no actual item in its place? Sure, we all have. When you ask the clerk if they’re really all out…if there are any “in the back,” what are you normally told? You’re told, “No, everything we have is out here; the item you want is going to be in on the next shipment.”

If you have had that happen to you, you’ve been exposed in small way to the downside (for the consumer) of just-in-time inventory. This method of cost control was established for the benefit of business, not the consumer, and the idea behind it is that retailers and manufacturers found they could save a lot of money by providing goods only as needed in real time, thus saving them a lot of money in the areas of inventory management and storage. Referring to the above example, the retail establishment keeps just as much as it has to on hand to occupy the shelves, which means it can save money on rent because it doesn’t need, in addition to the storefront, a large storage space in the back to hold inventory.

Just-in-time inventory does not exist simply at the individual, retail store level. If you go back one step from the store level, there’s the company warehouse from where store inventory is shipped, and JIT applies there, as well; the warehouse will keep as little product as it needs to on hand, which controls costs at that part of the supply chain. They will interact with manufacturers in such a way so that they receive product no sooner than needed, keeping inventory-related costs down all the way around.

JIT inventory is a great approach for business, but can be lousy for the consumer who needs goods in a pinch. In cases of sudden emergencies, store shelves will be emptied very quickly, and should the nature of the emergency be such that it interferes with the regular transport of goods to the now-empty retail locations, those who do not already have a healthy reserve of essentials could be in big trouble.

Keep this in mind, because it is how business is now done. Stock up now on emergency food reserves and other essentials, because should troubles descend on us very rapidly, there will be no time or opportunity for the unprepared to get prepared.